This invention relates to a scraper-chain conveyor, and in particular to a scraper-chain conveyor for use in inclined mine workings.
A scraper-chain conveyor is constituted by a plurality of channel sections joined together end-to-end. Each channel section has a pair of side walls which are joined together by means of a welded-in floor plate. The floor plates define a continuous conveying surface, which is usually positioned mid-way up the side walls. Consequently, the floor plates divide the conveyor into two regions, and the scraper assembly of the conveyor circulates in these regions. In the upper region (or run) the scrapers of the scraper assembly convey away won mineral material (such as coal), the lower region constituting a return run for the scrapers. The side walls of the channel sections are sigma-shaped, so that the two runs are defined by ducts of generally trapezoidal cross-section. These ducts serve to guide the scrapers which have a similar cross-section.
When such a scraper-chain conveyor is used in even fairly steeply inclined mine workings, there is the danger that pieces of material, such as lumps of coal, will slide down the upper flanges of the sigma-shaped side walls of the conveyor, without being slowed down by the scrapers. Obviously, this is undesirable, as it puts faceworkers and expensive mining equipment in danger of being hit by rapidly-moving pieces of mineral material. In very steeply inclined mine workings, there is the additional danger of pieces of mined material jumping out of the upper run of the conveyor.
In order to counteract the tendency of mined material to slide down the conveyor flanges or to jump out of the upper run, it is known to provide the conveyor with scrapers of very considerable height (see DE-GM 1872 409 and DE-GM 1870 416). In this case, the conveyor has to be jacked up, so it acquires a considerable total height. Obviously, this is disadvantageous as the conveyor occupies an excessive amount of the restricted space available in such mine workings.
The aim of the invention is to provide a scraper-chain conveyor for use in inclined mine workings, which conveyor does not suffer from these disadvantages, and which does not occupy too much space in a restricted mine working.